| Global warming is the increase in the | | | | scientists also disagree with parts of |
| average temperature of the Earth's | | | | them. |
| near-surface air and oceans in recent | | | | An increase in global temperatures can |
| decades and its projected continuation. | | | | in turn cause other changes, including |
| Global average air temperature near the | | | | sea level rise, and changes in the |
| Earth's surface rose 0.74 ± 0.18 °C | | | | amount and pattern of precipitation |
| during the past century. The | | | | resulting in floods and drought. There |
| Intergovernmental Panel on Climate | | | | may also be changes in the frequency and |
| Change (IPCC) concludes, "most of the | | | | intensity of extreme weather events, |
| observed increase in globally averaged | | | | though it is difficult to connect |
| temperatures since the mid-20th century | | | | specific events to global warming. Other |
| is very likely due to the observed | | | | effects may include changes in |
| increase in anthropogenic greenhouse gas | | | | agricultural yields, glacier retreat, |
| concentrations," which leads to warming | | | | reduced summer streamflows, species |
| of the surface and lower atmosphere by | | | | extinctions and increases in the ranges |
| increasing the greenhouse effect. | | | | of disease vectors. |
| Natural phenomena such as solar | | | | The term "global warming" is a specific |
| variation combined with volcanoes have | | | | example of the broader term climate |
| probably had a small warming effect from | | | | change, which can also refer to global |
| pre-industrial times to 1950, but a | | | | cooling. In common usage the term refers |
| small cooling effect since 1950. | | | | to recent warming and implies a human |
| These basic conclusions have been | | | | influence. The United Nations Framework |
| endorsed by at least 30 scientific | | | | Convention on Climate Change (UNFCCC) |
| societies and academies of science, | | | | uses the term "climate change" for |
| including all of the national academies | | | | human-caused change, and "climate |
| of science of the major industrialized | | | | variability" for other changes. The term |
| countries. The American Association of | | | | "anthropogenic climate change" is |
| Petroleum Geologists is the only | | | | sometimes used when focusing on |
| scientific society that rejects these | | | | human-induced changes. |
| conclusions, and a few individual | | | | |